Multi-inlet CH 4/Air flame with scheme GRI12 - Revision history

Seltz: /* DRGEP Step */

2019-01-31T15:59:22Z

‎DRGEP Step

Seltz: /* Key parameters */

2019-01-31T15:53:15Z

‎Key parameters

Seltz: /* Objectives */

2019-01-31T14:54:45Z

‎Objectives

Seltz: /* Optimisation Step */

2019-01-31T12:46:55Z

‎Optimisation Step

Seltz: /* Optimisation Step */

2019-01-31T12:44:45Z

‎Optimisation Step

Seltz: /* DRGEP Step */

2019-01-31T12:44:22Z

‎DRGEP Step

Seltz: /* QSS Step */

2019-01-31T12:44:03Z

‎QSS Step

Seltz: /* QSS Step */

2019-01-30T15:36:21Z

‎QSS Step

Seltz: /* DRGEP Step */

2019-01-30T15:33:08Z

‎DRGEP Step

Seltz: /* QSS Step */

2019-01-28T09:53:48Z

‎QSS Step

@@ Line 55: / Line 55: @@
 While running the DRGEP species step, your terminal should display the following information :
   Reading initial mechanism "mechanisms/gri12.xml" with description "gri12" ----------> OK
- Number of species: 32
- Number of reactions: 177
+  MECHANISM:------------------------------------------------------------------------------------------------------
- Set the mole fraction of inlet 0
+            Reading initial mechanism "mechanisms/gri12.xml" with description "gri12" ----------> OK
- Set the mole fraction of inlet 1
+               Number of species: 32
- Set the mole fraction of inlet 2
+               Number of reactions: 177

@@ Line 5: / Line 5: @@
 == '''Key parameters''' ==
-The target species considered for this test case are O2, CO and CO2. We are at atmospheric pressure, and the fuel is injected in its gaseous form (no evaporation model). The inputs of the 3 inlets (oxidiser, fuel and burned gases) are displayed below :
+The target species considered for this test case are O2, CO and CO2. We are at atmospheric pressure, and the fuel is injected in its gaseous form (no evaporation model). The inputs of the 3 inlets (oxidiser, fuel and burned gases) are displayed below (from the input_file.ini):
-Characteristics of the air inlet :
+ //------Inlets------//
-   listInlets.push_back(new MultipleInlet(
+ new Inlet 0 : Air
-                /*Temperature*/ 700,
+  T = 700
-                /*Pressure*/ 1E+05,
+  Pressure = 1E+05
-                /*Mass flow rate*/ 0.500,
+  MassFlowRate = 0.500
-                /*Xk*/ "O2:0.21, N2:0.79",
+  Xk = O2:0.21, N2:0.79
-                /*Yk*/ "",
+  // the composition can also be added with molar fractions, for that replace "Yk" by "Xk"
-                /*Evaporation model*/ false,
+  EvaporationModel = false
-                /*Droplet diameter*/ 0.0,
+  DropletDiameter = 0.0
-                /*Evaporation time*/ 0.0,
+  EvaporationTime = 0.0
-                /*Liquid density*/ 0.0,
+  liquidDensity = 0.0
-                /*Evaporation latent heat*/ 0.0));
+  EvaporationLatentHeat = 0.0
-Characteristics of the burned gases inlet :
+ new Inlet 1 : Fuel
-   listInlets.push_back(new Characteristics_MultipleInlet(
+  T = 450
-                /*Temperature*/ 2500,
+  Pressure = 1E+05
-                /*Pressure*/ 1E+05,
+  MassFlowRate = 0.017
-                /*Mass flow rate*/ 0.200,
+  Xk = CH4:1.0
-                /*Xk*/ "N2:0.76308, O2:0.093573, H2O:0.072355, CO2:0.070468",
+  // the composition can also be added with molar fractions, for that replace "Yk" by "Xk"
-                /*Yk*/ "",
+  EvaporationModel = 0
-                /*Evaporation model*/ false,
+  DropletDiameter = 0.0
-                /*Droplet diameter*/ 0.0,
+  EvaporationTime = 0.0
-                /*Evaporation time*/ 0.0,
+  liquidDensity = 0.0
-                /*Liquid density*/ 0.0,
+  EvaporationLatentHeat = 0.0
-                /*Evaporation latent heat*/ 0.0));
+ //EndInlet
-                /*tau_t*/ 2e-04,
-                /*delta_t*/ 1e-05,
-                /*nbIterations*/ 200,
+ new Inlet : GB
-                /*BurnedGases*/ true));
+  T = 2500
 == '''Results''' ==

@@ Line 1: / Line 1: @@
 == '''Objectives''' ==
-The Stochastic_GRI12 test case describes a reduction of the GRI1.2 scheme for a 0D 2-inlet configuration. Starting with 32 species and 177 reactions, we reduce to 12 transported species, 2 species in quasi steady state assumption and 29 reactions.
+The Stochastic_GRI12 test case describes a reduction of the GRI1.2 scheme for a 0D 2-inlet configuration. Starting with 32 species and 177 reactions, we reduce to 12 transported species, 2 species in quasi steady state assumption and 28 reactions.
 == '''Key parameters''' ==

@@ Line 232: / Line 232: @@
-The final step of the ORCh method, the genetic algorithm, enables to recover the trajectories of the target species. Firstly, we allowed a 10 % variation on the pre exponential factor, the temperature exposant and the energy activation in order to find their optimal values.
+The final step of the ORCh method, the genetic algorithm, enables to recover the trajectories of the target species. We allowed a 10 % variation on the pre exponential factor, the temperature exposant and 6 % on the energy activation in order to find their optimal values.
-A population of 40 elements was used during 38 generations.
+A population of 40 elements was used during 40 generations.
-The following trajectories of the temperature, the flame speed and the target species match perfectly the ones of the reference detailed scheme with only 12 transported species and 29 reactions.
+The following trajectories of the temperature, the flame speed and the target species match perfectly the ones of the reference detailed scheme with only 12 transported species and 28 reactions.

← Older revision		Revision as of 12:44, 31 January 2019
Line 243:		Line 243:
	[[File:optim_stoch_GRI.png\|600px\|center]]		[[File:optim_stoch_GRI.png\|600px\|center]]

−	Fig4 : Comparison between the reference trajectories of the target species and the temperature (in black), and the trajectories computed with the reduced mechanism with 12 transported species and 29 reactions (in red) after optimisation for the fuel inlet.	+	Fig4 : Comparison between the reference trajectories of the target species and the temperature (in black), and the trajectories computed with the reduced mechanism with 12 transported species and 28 reactions (in red) after optimisation for the fuel inlet.

@@ Line 173: / Line 173: @@
 [[File:14sp_28R.png|600px|center]]
-Fig2 : Comparison between the reference trajectories of the target species and the temperature (in black), and the trajectories computed with the reduced mechanism with 14 transported species and 29 reactions (in red) for the fuel inlet.
+Fig2 : Comparison between the reference trajectories of the target species and the temperature (in black), and the trajectories computed with the reduced mechanism with 14 transported species and 28 reactions (in red) for the fuel inlet.
 === QSS Step ===

@@ Line 223: / Line 223: @@
 We choose to put the species CH3O and HCO in QSS hypothesis due to their low QSS coefficient.
-In order to obtain the trajectories of the 12-transported species 29-reactions reduced scheme, we run the getQSSfile step and we observe that the final state and the shape of the trajectories are conserved. It is under these conditions that the optimisation step will be efficient.
+In order to obtain the trajectories of the 12-transported species 28-reactions reduced scheme, we run the getQSSfile step and we observe that the final state and the shape of the trajectories are conserved. It is under these conditions that the optimisation step will be efficient.
 [[File:12sp_28R.png|600px|center]]
-Fig3 : Comparison between the reference trajectories of the target species and the temperature (in black), and the trajectories computed with the reduced mechanism with 12 transported species and 29 reactions (in red) for the fuel inlet.
+Fig3 : Comparison between the reference trajectories of the target species and the temperature (in black), and the trajectories computed with the reduced mechanism with 12 transported species and 28 reactions (in red) for the fuel inlet.
 === Optimisation Step ===

@@ Line 169: / Line 169: @@
   Reaction 27  0.992507
-After this step, by comparing the reference trajectories with the new ones, we choose to delete 13 reactions, so the next step is performed with 14 species and 29 reactions. Indeed, with 28 and less species, the final state of the trajectories is not well predicted and difficult to represent even with the optimisation step.
+After this step, by comparing the reference trajectories with the new ones, we choose to delete 13 reactions, so the next step is performed with 14 species and 28 reactions. Indeed, with 27 and less species, the final state of the trajectories is not well predicted and difficult to represent even with the optimisation step.
-[[File:14sp_29R.png|600px|center]]
+[[File:14sp_28R.png|600px|center]]
 Fig2 : Comparison between the reference trajectories of the target species and the temperature (in black), and the trajectories computed with the reduced mechanism with 14 transported species and 29 reactions (in red) for the fuel inlet.

@@ Line 179: / Line 179: @@
 While running the QSS step, your terminal should display the following information :
-  Species H  0.00707074
+  Species H  0.00794323
-  Species O  0.00347138
+  Species O  0.00490131
   Species O2  1
-  Species OH  0.00238597
+  Species OH  0.00320187
-  Species H2O  0.0394215
+  Species H2O  0.0582805
-  Species HO2  0.0120837
+  Species HO2  0.012535
-  Species CH3  0.0951441
+  Species CH3  0.0853549
-  Species CH4  0.774634
+  Species CH4  0.794206
   Species CO  1
   Species CO2  1
-  Species HCO  0.00480146
+  Species HCO  0.00362124
-  Species CH2O  0.178736
+  Species CH2O  0.181152
-  Species CH3O  0.00520346
+  Species CH3O  0.00472456
   Species N2  1
-  Interactions with species H  with QSS Criteria 0.00707074
+  Interactions with species H  with QSS Criteria 0.00794323
   H2O:2  HO2:1  CH3:1  CH2O:2  CH3O:1
-  Interactions with species O  with QSS Criteria 0.00347138
+  Interactions with species O  with QSS Criteria 0.00490131
   OH:1  H2O:1  HO2:1  CH3:1  CH2O:1  CH3O:1
-  Interactions with species OH  with QSS Criteria 0.00238597
+  Interactions with species OH  with QSS Criteria 0.00320187
-  O:1  OH:2  HO2:1  CH3:2  HCO:2  CH2O:2  CH3O:1
+  O:1  OH:2  HO2:1  CH3:2  HCO:1  CH2O:2  CH3O:1
-  Interactions with species H2O  with QSS Criteria 0.0394215
+  Interactions with species H2O  with QSS Criteria 0.0582805
   H:2  O:1  HO2:1  CH3:1  HCO:2
-  Interactions with species HO2  with QSS Criteria 0.0120837
+  Interactions with species HO2  with QSS Criteria 0.012535
   H:1  O:1  OH:1  H2O:1  CH3:2  CH2O:1
-  Interactions with species CH3  with QSS Criteria 0.0951441
+  Interactions with species CH3  with QSS Criteria 0.0853549
   H:1  O:1  OH:2  H2O:1  HO2:2  HCO:1  CH2O:1
-  Interactions with species HCO  with QSS Criteria 0.00480146
+  Interactions with species HCO  with QSS Criteria 0.00362124
-  OH:2  H2O:2  CH3:1
+  OH:1  H2O:2  CH3:1
-  Interactions with species CH2O  with QSS Criteria 0.178736
+  Interactions with species CH2O  with QSS Criteria 0.181152
   H:2  O:1  OH:2  HO2:1  CH3:1
-  Interactions with species CH3O  with QSS Criteria 0.00520346
+  Interactions with species CH3O  with QSS Criteria 0.00472456
   H:1  O:1  OH:1